Group finally visit port city (4)
I believe the answer is:
trio
'group' is the definition.
(a group of three)
'finally visit port city' is the wordplay.
'finally' says to take the final letters.
'port city' becomes 'Rio' (Rio de Janeiro).
The final letter of 'visit' is 't'.
't'+'rio'='TRIO'
(Other definitions for trio that I've seen before include "wise men?" , "Threesome" , "(Composition for) three performers" , "Beethoven's 'Archduke': famous piece written for this ensemble" , "Work for three" .)